Sealing arrangements, also known as seal assemblies, are used on a regular basis in turbomachines, such as airplane engines, for sealing a radial gap between rotating engine components and stationary engine components. They permit a damage-free running-in of blade tips, sealing webs and the like, and they result in a reduction of leakage streams.
Known sealing arrangements comprise a plurality of sealing segments each consisting of a honeycomb element and a base body for accommodating or holding the honeycomb element. The base body can be an integral body section of an engine component, such as an outer shrouding band of a rotor blade, or an individual component which is mounted on a rotor- or stator-side supporting section, such as, for example, a radial collar of a rotor hub, opposite a stator blade.
The honeycomb element and the base body are usually produced separately from each other and are subsequently connected to each other by high-temperature soldering in a vacuum. The base body is often a solid body which is produced preferably from a high temperature resistant nickel alloy. The honeycomb element usually consists of a plurality of reshaped metal plates that are interconnected to form honeycombs. The separate production of the honeycomb element and of the base body simplifies their formation; however, during the soldering process a distortion of the honeycombs can occur, so that their diameter has to be machine finished, for example, by regrinding. The regrinding is particularly expensive if the base body is an integral body section, such as, an outer shrouding band of a stator blade or a rotor blade, since the clamping and handling of the stator blade is complicated. In addition, the replacement of individual sealing segments is expensive due to the material lock connection. If the base body is mounted on a supporting section, this usually occurs via a sliding engagement in the peripheral direction, as a result of which, when one of the sealing segments is replaced, several sealing segments have to be disassembled from the supporting sections. The metal plate reshaping in addition limits the freedom of design of the sealing segments and that of the sealing arrangement, and as a result construction related compromises have to be made. Moreover, the construction related compromises have a disadvantageous effect on their sealing effect and on the weight of the sealing segments. In addition, the construction of the sealing segments is determined by the connection of the honeycomb element to the base body.
From the German Patent DE 10 259 963 B4, a honeycomb seal is known, whose sealing segments are produced in a single piece by powder metallurgical injection molding. This method allows a flexible freedom of design to the greatest extent possible but the injection molding requires a relatively high expenditure for technical equipment.
A need therefore exists, for a sealing arrangement that eliminates the above-mentioned disadvantages and is easy to assemble and disassemble. Moreover, a need also exists for a method for the simplified production of a sealing segment as well as an efficient turbomachine.